ABSTRACT The objective of Proteomics Core B is to provide state of the art mass spectrometry-based proteomic capabilities, dedicated analytical support, and mentorship to the investigators funded through the SC COBRE in Oxidants, Redox Balance, and Stress Signaling (Redox COBRE). Mass spectrometry is a powerful technology enabling unbiased discovery of the effects of drugs/ligands, genetic alterations, and disease on changes in protein expression, protein interactions, and post-translational modifications. Post-translational modifications encode the nutrient and stress status of the cell and mediate acute responses to ligand stimulation and changes in redox status by influencing protein function, half-life, and localization. The MUSC Mass Spectrometry Facility and Proteomics Center have an extensive array of instrumentation for protein characterization and expertise in applying proteomic technologies to biomedical research endeavors. During the last funding period acquisition of an Orbitrap Elite mass spectrometer, purchased through a shared instrumentation grant, enabled us for the first time to apply quantitative proteomic approaches to the detection of complex post-translational modifications. In ongoing collaborative projects with COBRE investigators and participants in the Redox Center, Proteomics Core B is utilizing the Orbitrap Elite to examine the global effects of altered redox status on protein expression, phosphorylation, acetylation, and thiol modifications and to characterize the sites of phosphorylation, S-glutathionylation, tyrosine nitration, and protein crosslinking on redox-sensitive target proteins. The specific aims of Proteomics Core B are: 1) to assist COBRE investigators with experimental design including sample preparation strategies and choice of specific proteomic approach, 2) to customize data acquisition and analysis to address the goals of the individual projects, and 3) to provide mentorship and training in the applications of proteomic technologies for future projects. Access to these capabilities and expertise to push the available technology forward is critical to the proposed research projects. The experimental capabilities and infrastructure established with COBRE investigators are made available to investigators at MUSC and other institutions in South Carolina that utilize the MUSC Mass Spectrometry Facility. Our goals are to provide COBRE investigators with access to instrumentation and expertise to advance their research and contribute to the success of our promising junior faculty.